Currently, a general HTML (Hyper Text Markup Language) browser can perform session management when connecting to the same site (for example, it is realized by utilizing a technique such as Cookie defined in RFC (Request for Comments) 2965). When the HTML browser connects to a plurality of sites, a plurality of servers that provide the plurality of sites need to perform some processing. For example, if the servers can perform session management, connection to the plurality of sites can be realized (for example, refer to patent document 1).
As conventional technologies that realize single sign-on using a single HTML browser, “Liberty Alliance” is known as a method for managing ID (identifier) in a distributed manner, and “.Net Passport” is known as a method for managing ID in a centralized manner.
[Patent document 1] Japanese Laid-Open patent application No. 2002-335239 (Paragraphs 0053-0058, etc.)